From Flow Instability to Flow-Induced Excitation

Although most flow-induced vibrations of structures have their ultimate origin in an instability of the flow, they comprise a multitude of complex and seemingly unrelated flow phenomena. An attempt is made to show that common to all these phenomena are a few essentially identical excitation or control mechanisms: extraneous control through periodic disturbances and self-control involving either fluid-dynamic, fluid-resonant, or fluid-elastic feedback. The significance and general characteristics of these mechanisms are examined in detail and illustrated by various modifications of a submerged two-dimensional jet as well as by numerous examples of familiar flow-induced excitations.